Bump maven-jar-plugin from 3.2.0 to 3.2.1 (#52)

planetiler-core/pom.xml

@@ -137,7 +137,7 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-jar-plugin</artifactId>
-          <version>3.2.0</version>
+          <version>3.2.1</version>
           <executions>
             <execution>
               <goals>